GT80 review by Crate

Sound — 8
I use this amp with simple guitar styles because I'm a n00b and I mainly play grunge, which doesn't use many special techniques beyond hammer-ons, pull-offs, and alternate picking. I use it with just my standard Squier xD with its single coil pickups, ya know. It can be very loud, but also it can be used on a quiet setting as well; it's fairly versatile when it comes to volume. The amp can make sludgy, almost heavy metal sounds with just the channel switch activated, similar to the sounds of Helmet. With the solid state/tube switch, it sounds not quite as heavy; kind of like Nirvana's less distorted songs. However, the amp doesn't seem to work very well past roughly 20 minutes of use; the sound fades in and out, quits, and then gets very loud, and sometimes very quiet. Once again, I don't know if this is just my amp or if they all have that problem. However, scouring the internet, I did find several others with this problem.

Overall Impression — 8
This amp is a very good match for the style of music I play, because it can get heavy enough for metal, and it has a good grunge sound to it as well. I've only been playing for a couple months at this point, and I don't own much other gear except for a worthless mini amp Fender included with my crappy Squier. I don't know if I would buy this again if it were stolen or lost; I would have to do more research for the problem with the audio.

Reliability & Durability — 6
I can kind of depend on this amp, but not if I were to use it in a gig. I would definitely need a backup if I were to play a gig, because the sound messes up after a little while. The amp has never completely broken down, though it does have problems aforementioned.

Features — 10
Unfortunately, I don't know the year this was made. The amp is fairly versatile for the styles of music I play; grunge, and metal. It has a headphone jack, but strangely, when you plug in headphones, the sound comes out of both the headphones and the amp itself. I don't know if it's just my amp because I believe it's fairly old. It has a lead channel and a rhythm channel, and you can change the volume and level of sound from high, medium, and low notes for both settings. It also comes with a solid state/tube knob which can be used with the channel knob. The channel knob can also be used without the solid state/tube knob. You can change if you are using solid state or tube for both the rhythm and lead settings, and how much of each. I wish it had a fuzz feature because a lot of the songs I play use fuzz. I also wish it had wah, but that does not sound very common to me in just an amp and not with pedals. I use this amp for practice, and it is definitely powerful enough; it can be heard throughout the whole house on low.

Yes, I bought a GT-80 for my first "real" amp back when they were newly available in 1991 or 1992. It was a little loud (lol) for my bedroom at my folks' house, and after swapping in some new Groove Tubes, the tone blew me away. (I had just bought a fire-engine red American Standard strat, too.)
And the fact that you have so many tonal options with the tube/ss preamp and separate tone stacks makes it so versatile.
I'm very happy I decided to buy it when I did.